I was thinking you probably use Adobe Premiere and/or Adobe After Effects, but I'm not sure at all.
Also, how hard will it be? I have some basic experience with Photoshop and Illustrator if it matters.
Based on the link you added in your comment, I would say you could use After Effects, and Premiere for this very easily...there may be easier/cheaper solutions but essentially what you are going for is pretty easy to make
Graphic designing aside you could probably learn and do this in a day or two, if you have any sort of background in photoshop or computers.
Start here, I am pretty sure this is where I learned how to use After Effects http://www.videocopilot.net/basic/